Process of utilizing carbonic acid



p 1929- H. DEHOTTAY 1,727,865

PROCESS OF UTILIZING CARBONIC ACID Filed Nov.. 28, 1927 Patented Sept. 10, 1929.

PATENT OFFICE,

HENRI DEHOTTAY, OF MALMEDY, BELGIUM.

PROCESS OF UTILIZING CARBONIC ACID.

, Application filed November 28, 1927, Serial No. 236,293, and in Belgium April 9, 1927.

This invention relates to a method and apparatus for the utilization of carbonic acid.

Ordinarily carbonic acid for commercial uses is delivered in a liquid state under the disadvantages incident to the employment of special tanks to resist the pressure, transportation charges, the requirement for special valves and other details; and in the attempt to avoid these undesirable expenses, which tend to increase the ultimate cost of the acid, attempt has been made to ship the acid in a .solid form, that is, in the form of compressed blocks commercially known as carbonic acid snow, but in this method of transporting the acid, no provision, so far as known to me, has yet been made for converting this solid acid into the gaseous form, for use in situations where the gas is required.

The primary object of the present invention is to permit the transportation of the acid in solid form and to convert said acid 1n a more or less automatic manner into a liquid or gaseous state, or partly both, and

permit the selective use of the gas or liquid as may be necessary.

In carrying out the method, the acid transported to the place of use in a solid form, is placed at such point of use in one or more vessels which are thereafter tightly closed. The heat exchange between the walls of the vessel and the solid acid rapidly converts a portion of such solid acid into a gaseous state, thereby generating pressure which will materially assist in the further gasifying of the solid content. If, as experionce has demonstrated, the exchange of heat between the solid acid and the walls of the vessel is insufficient to liquefy the full solid content of the vessel, the heat exchange is continued through the Wall of the vessel from the surrounding air, with the result that in a comparatively short time the entire solid acid mass is rendered liquid and gaseous. the exterior of the vessels may be subjected to passages of heated or even atmospheric air or water flowing over the same in order to It the process is to be hastened,

increase the heat exchange and more rapidly convert the solid acid. I

. An apparatus for carrying out the improved method is illustrated in the accoinpanying drawing, in which 1 indicates steel vessels stationed at the place at which the acid is to be used as a liquid or gas. Th tops 2 of these vessels are removable to permit the introduction of the solid acid from the containers in which it is shipped, suvh covers being thereafter fixedly secured in place. For example, the covers may he threaded onto the vessels, and it is understood that the vessels, covers and the connections between the covers are of a character to resist the pressure to which they may be subjected on the conversion of the solid acid to a gaseous statc A. delivery pipe 7 for the delivery of the gaseous content of one or all of the tanks is connected to each tank by a pipe connection 8 leading into the tank near the cover 2, a valve 5 being utilized to control the connection between the pipe 7 and each tank. A corresponding delivery pipe 8, which may serve for delivering carbonic acid in liquid state, is connected by means of a pipe 4 to each of the tanks 1 at the lowest point thereof, a valve 6 controlling each tank communication with the pipe 8.

Each tank may be provided with a pressure gauge and thermometer (not specifically shown but indicated at 10) whereby the pressure and temperature of each tank may be readily determined by the operator. Furthermore, each tank may be provided with a safety valve 11 which valves communicate with a common pipe 12 leading to any suitable collector to avoid loss. Furthermore, each tank may have an independent' outlet at the upper end controlled by a valve 13 and a similar independent outlet at the lower end controlled by a valve 14 permitting the filling up or emptying of any one of the tanks irrespective of the conditions of the others.

After the vessels 1 have been charged with the carbonic acid in solid form, the exchange of heat between the walls of the vessels and such carbonic acid serves to til.)

rapidly convert a portion of the solid acid into a gaseous state. This, of course, im-

mediately increases the pressure upon the remaining solid content andthere is-a fol- ,lowing conversion of the remaining solid acid intoa liquid state. The metallic character of the vessels, however, provides for a continued and intense exchange of heat between the surrounding air and the solid or liquid acid, so that within a comparatively short time the entire solid content of the tank or tanks is converted into-a partly liquid and partly gaseous form. If desired,

the heat exchange necessary for the conversion may be mechanically facilitated by causing air currents, either. heated or at ordinary temperature, to be driven over and past the tanks, or causing water to flow or trickle over the tanks.

The invention contemplates the use of but a single tank 1 where a limited use only is required or the provision of such number of tanks as will take care of the particular situation. By means of the outlets 3 and 4, it is of course obvious that the vessels between the several tanks, if a number are used, maybe readily balanced in order that each will be subjected to more or less. similar pressure.

, Having thus described the invention, what is claimed as new is:

1. A method for the utilization of carbonic acid forwarded to the place of use in a solid form, comprising the confining of the acid in a solid form in a heat conducting vessel and permitting the heat exchange between the vessel and acid and be-- tween the surrounding air and acid through the wall of the vessel to convert said solid acid into a gaseous state. J i 2. A method for the. utilization of carbonic acid forwarded to the place of use in a solid form, comprising the confining of .the acid in a solid form in a heat conductingvessel and permitting the heat exchange between the vessel and acid and between the surrounding air and acid through the wall of the vessel to convert said solid acid into a gaseous state, and further assisting the conversion of the solid acid by the pressure generated in the vessel in the initial conversion of the solid acid to the gaseous state.

g In testimony whereof I aflix my signature.

HENRI DEHOTTAY. 

